1. Field of the Invention
This invention relates in general to installing pre-hung doors and more particularly, to a device that properly aligns and shapes a pre-hung doorframe during installation within a rough opening in a wall.
2. Description of the Related Art
In building construction, in which doors are to be installed, the building contractors leave rough openings in the walls where finish carpenters, according to the architectural plans for the building, will later install the doorframes and doors. Doorframes generally consist of a head jamb spanning the distance between two side jambs and must be installed so that the jambs are completely plumb, or vertical, the head jamb is horizontal, the entire frame is square, and all parts of the frame are in the same plane. The jambs are secured in place with nails or screws to studs forming the rough opening in the wall. Once the frame is secured to the rough opening, a door or set of doors are then attached to the frame. However, the frame material is relatively thin and the four corners, where the rectangularly arranged sections meet and are attached to each other, do not present a great deal of surface area for bonding. Therefore, the frame is prone to twisting, warping, bending, and separating during the installation stage. If the frame is not completely square, the door will not swing true and will not close properly. This can result in gaps between the door and the frame, the doors hitting the frame or floor, or not closing properly.
Pre-hung doors are well known by those in the art. Pre-hung doors are factory-manufactured doors, which include a door attached by hinges to a preassembled jamb. One technique of installing the pre-hung door and frame in a proper alignment is to place the door in the rough opening, which will be larger than the frame, center it in the frame, use a level on the jambs to ensure proper alignment, place shims between the jambs and the studs to properly space each end of the jamb from the studs to achieve vertical or horizontal alignment, and then screw or nail the frame to the shims and, in turn, the shims to the studs. This method is difficult and time consuming even for a skilled carpenter. To achieve any level of efficiency, this method requires two carpenters, one to hold the level and the jamb and the other to install the shims and screw the frame to the studs. Additionally, this method does not ensure that the frame is installed in a single plane.
Several prior-art devices have been introduced to improve upon the above-described process. One such device is Tuthill (U.S. Pat. Pub. No. 2004/0000061 A1), which discloses an apparatus for installing a frame and related appurtenances incorporating four corner members slidably and releasably joined with height and width adjusters. The Tuthill apparatus is placed within a preassembled doorframe and then placed within a rough opening in a wall. The apparatus keeps the frame square while it is shimmed and secured to the wall. The Tuthill apparatus, however, suffers from the disadvantage of only securing the frame to the apparatus in one direction with a frame member 110, allowing a section of the frame to slide out of skew during installation. Additionally, the floor of the building may not be perfectly level, however, the door must be. Therefore, the height from the floor to each side of the bottom of the frame will need to be set before securing the frame in the rough opening. The distance from the floor to the apparatus in Tuthill is constant and is set by the dimension of a strike side base frame section 144. If the floor is not level, the frame tilt will follow the floor.
Finally, the Tuthill apparatus has a horizontal adjustable brace 270. The presence of the brace prevents a worker from passing through the doorway opening during the installation process. This presents a difficulty to the carpenter who may need to work from both sides of the doorway to install the frame. It also prevents other workers from being able to pass through the opening while the device is in place, possibly slowing progress on other areas of the building. Other prior art doorframe-hanging devices that suffer from this same disadvantage are: Washington (U.S. Pat. No. 773,176), Durkee (U.S. Pat. No. 1,257,2000), Hansen Jr. (U.S. Pat. No. 1,627,175), Hobbs (U.S. Pat. No. 1,778,496), Reeder Jr. (U.S. Pat. No. 2,679,696), Williams (U.S. Pat. No. 2,748,493), Appleton (U.S. Pat. No. 3,675,297), Stein (U.S. Pat. No. 5,167,073), and Stein et al. (U.S. Pat. No. 5,560,112).
Another prior art device is disclosed in Cloutier et al. (U.S. Pat. No. 6,237,233), which shows a doorframe adjustment apparatus that is horizontally collapsible. The Cloutier et al. device also suffers from some of the same disadvantages as does the Tuthill device. First, there are no clamping members to secure the frame to the device and preventing it from sliding relative to the edges of the device. As can be seen in FIG. 4 of Cloutier et al., members 2 and 3 may prevent movement of the frame in a first direction, toward the members, but nothing prevents the frame from sliding in a second direction away from the members 2 and 3. Secondly, the device does not provide a means for adjusting the height of the device, and therefore the frame, from the floor surface. Additionally, the Cloutier et al. device suffers from the disadvantage that it is not vertically collapsible and is therefore difficult to move, store, and remove from the door opening after the frame is secured. Finally, because the device is fixed in the vertical dimension, it cannot accommodate doors of varying size. This particular disadvantage is shared by the doorframe-hanging devices disclosed in Torstensen (U.S. Pat. No. 6,530,186) and McKay (U.S. Pat. No. 2,502,166).
Accordingly, a need exists for a construction tool for installing pre-hung doors that is adjustable in length and width to accommodate doors of varying dimensions and is capable of securely holding and properly aligning a doorframe during installation in a rough opening in a wall, while at the same time, allowing a worker to pass through the doorway opening.